1. Field of the Invention
The present invention relates to a package, and more particularly, to a quad flat no lead (QFN) package.
2. Description of the Related Art
FIG. 1 is a schematic view of a conventional QFN package. As shown in FIG. 1, the conventional package 100 comprises a die pad 101, a chip 102, a plurality of pads 103, a plurality of wires 104 and an encapsulation material 105. The chip 102 is mounted on the die pad 101. The pads 103 circumvent the die pad 101. The chip 102 is electrically connected to the pads 103 through the wires 104. The encapsulation material 105 covers the die pad 101, the chip 102, the pads 103 and the wires 104, wherein the bottom surface of the die pad 101 and the bottom surfaces of the pads 103 are exposed, and the exposed bottom surfaces of the pads 103 serve as external terminals.
Uncovering of the bottom surfaces of the die pad 101 and the pads 103 by the encapsulation material 105 exposes the bottom surfaces of the die pad 101 and the pads 103 to the air. The joints between the wires 104 and the pads 103 which are closer to the outside environment are likely to be damaged, thus decreasing the reliability of the conventional package 100, since the encapsulation material 105 tends to absorb moisture. Additionally, since the pads 103 circumvent the die pad 101, the amount of inputs/outputs terminals is limited in the conventional package 100 with a fixed size. If the amount of inputs/outputs terminals is intentionally increased in the conventional package 100, the amount of the pads 103 circumventing the die pad 101 must be increased, thus the size of the conventional package 100 must be enlarged.
Consequently, there is an existing need for a quad flat no lead package that solves the above-mentioned problems.